Joshi Madalsa, Dillman Jonathan R, Towbin Alexander J, Serai Suraj D, Trout Andrew T
Department of Radiology, British Columbia Children's Hospital, Vancouver, BC, Canada.
Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229-3026, USA.
Pediatr Radiol. 2017 Jun;47(7):838-843. doi: 10.1007/s00247-017-3831-z. Epub 2017 Apr 3.
Magnetic resonance (MR) elastography allows the noninvasive assessment of liver stiffness, which is a surrogate for fibrosis.
The purpose of this study was to describe our experience using liver MR elastography in a large pediatric population with attention to the frequency and causes of exam failure.
Imaging records were searched for patients ≤18 years of age who underwent 2-D gradient recalled echo (GRE) MR elastography of the liver between September 2011 and August 2015 on one of two 1.5-T MRI platforms. Imaging reports and clinical records were reviewed for failed MR elastography acquisitions, factor(s) resulting in failure and whether a subsequent successful examination had been performed.
Four hundred sixty-eight MR elastography examinations were performed in 372 patients between 1.5 months and 18 years of age during the study period. Ninety-six percent (450/468) of the examinations were successful. There was no significant difference in mean age (12.6±3.6 vs. 11.2±4.1 years, P=0.12) or body mass index (BMI) (28.2±12.4 vs. 29.5±10 kg/m, P=0.6) between patients with and without successful examinations. MR elastography failures were due to poor paddle positioning resulting in inadequate generation of hepatic shear waves (n=5), iron overload (n=4), patient inability to tolerate MRI (n=3), patient breathing/motion (n=3), artifact from implanted hardware (n=1) and technical malfunction (n=2). Seven of nine (78%) repeat examinations were successful (78%).
Hepatic 2-D GRE MR elastography at 1.5 T is technically robust in children. Exam failure is infrequent and largely reflects patient specific factors, some of which can be mitigated with careful technique.
磁共振弹性成像可对肝脏硬度进行无创评估，而肝脏硬度是纤维化的一个替代指标。
本研究旨在描述我们在大量儿科人群中使用肝脏磁共振弹性成像的经验，重点关注检查失败的频率及原因。
检索2011年9月至2015年8月期间在两个1.5T磁共振成像平台之一上接受肝脏二维梯度回波（GRE）磁共振弹性成像检查的18岁及以下患者的影像记录。回顾影像报告和临床记录，以了解磁共振弹性成像采集失败情况、导致失败的因素以及是否进行了后续的成功检查。
在研究期间，对372例年龄在1.5个月至18岁之间的患者进行了468次磁共振弹性成像检查。96%（450/468）的检查成功。成功和未成功检查的患者之间，平均年龄（12.6±3.6岁 vs. 11.2±4.1岁，P = 0.12）或体重指数（BMI）（28.2±12.4 vs. 29.5±10kg/m²，P = 0.6）无显著差异。磁共振弹性成像失败的原因包括：探头定位不佳导致肝脏剪切波生成不足（n = 5）、铁过载（n = 4）、患者无法耐受磁共振成像（n = 3）、患者呼吸/运动（n = 3）、植入硬件产生的伪影（n = 1）和技术故障（n = 2）。9次重复检查中有7次（78%）成功。
1.5T的肝脏二维GRE磁共振弹性成像在儿童中技术上是可靠的。检查失败很少见，主要反映患者的特定因素，其中一些因素可通过仔细的技术操作来缓解。
